DE696030C - Process for operating gas machines with gas from fuels which can be liquefied under pressure at air temperature, but are gaseous at normal air pressure - Google Patents

Description

Method for operating gas engines with gas from fuels that liquefiable under pressure at air temperature, at normal air pressure but are gaseous It has been found that the operation. of internal combustion engines, z. B. vehicle engines, with liquefied fuel gases, which at air temperature below Pressure effect liquefiable, but are gaseous at normal air pressure, in more advantageous This can be done if the liquefied fuel is in this condition injected directly into the working cylinder. The one during relaxation or gassing As is known, considerable heat consumption does not lead to freezing and to other annoyances, rather the relaxation and evaporation heat have an effect here on the filling weight and also on the combustion character of the cargo (cf. the so-called internal cooling and compressor effect of the heat of vaporization fuels containing alcohol). It is therefore in the present method Heat consumption relocated to the inside of the engine through relaxation and an uneconomical one and cumbersome preheating avoided.

The present procedure differs significantly from those Working methods in which ordinary liquid fuels are in the working cylinder are injected, as is the case with diesel engines and the experimental ones occasionally manufactured injection engines for gasoline and similar liquid fuels of the Case is. The heat of vaporization does not play a role in diesel engines, in injection engines only a relatively minor role, while only with liquefied fuel gases a considerable increase in filling due to the expended heat of expansion and evaporation entry. Furthermore, however, only liquefied fuel gases are made possible by virtue of their rapid and voluntary transformation into gas and its own pressure, if necessary, the omission the expensive and difficult to operate metering injection pump with its immensely high (about 100 atmospheres) injection pressures and correspondingly narrow and sensitive to operation Nozzle holes.

Up to now it has been customary to use liquefied liquids used to operate internal combustion engines To evaporate fuel gases first and then to supply the combustion chamber as gases or to allow the engine to suck in the gases. the in relaxation The cooling that occurs in the liquefied fuel gases inhibits the gasification and can even lead to freezing of the evaporator. That is why such evaporators are for example with waste heat from the engine or even by heating the evaporator with combustion a branched off part of the fuel gas is artificially heated.

It is also known to use fuel gases released in this way (and Incidentally, oxygen released in the same way) from the internal combustion engine to add self-generated exhaust gases to feed them back into the engine.

By introducing the fuel gas in liquid form according to the present process, an increase in the filling weight and thereby the performance is achieved. If z. If, for example, instead of a mixture of g % fuel gas and 95 ° 1o combustion air, an engine only sucks in pure air and the fuel gas is fed to the cylinder with the valves closed, the filling weight increases by approximately 5 %. In addition, the introduction of the liquid fuel gas causes the working cylinder to cool down and thus indirectly to a further increase in the filling weight. With the same fuel, such cooling allows an increase in compression and thereby in performance and economy, as is well known from carburetor engines and internal combustion fuels.

Another advantage of the present method is that the devices for eliminating the expansion and evaporation heat completely come to an end. These facilities are costly, space-consuming and fragile.

To carry out the method, the cylinder space can be attached to a suitable Place, which is located both in the combustion chamber and on the cylinder liner can be provided with a connection for the liquefied gas, which by a special control element, which in appropriate cases also by the working piston the machine itself can be implemented, is controlled accordingly. The control the amount of fuel can also be mechanical as a function of the engine speed for example be done in such a way that a motor-driven pumping station with adjustable Useful stroke is switched on in the line of the liquefied fuel gas.

The control can also be advantageously operated by magnetically actuated Valves take place.

The injection time can be set very differently. she needs not to begin with the suction stroke, but can also take place in the compression stroke, whereby the increasing compression pressure automatically counteracts the further outflow.

Control can be effected in any convenient manner, either as mixture volume control (coupling of a throttle element in the fresh air line with the control element of the gas supply and a fuel or speed-dependent element) or as a quality control (changing the fuel supply without changing the Air cross-sections) or something in the middle between the two principles, that a coarse regulation of the air filling takes place depending on the fuel supply. The quality control has the advantage of full compression even with throttling capacities and thereby to result in more favorable consumption figures than the mixture quantity regulation.

It can be used to achieve good idling and good combustion - especially in the case of quality control - it can be advantageous to reduce the fuel supply completely or to effect partly in the vicinity of the spark plug.

This makes it possible when operating with a single fuel to achieve clean idling and the economically advantageous quality control (Change in the amount of fuel without a significant change in the amount of air) realize.

To secure it, it is advisable to place between the fuel tank and the working cylinder apart from a non-return valve to install a throttle device, which no longer fuel passes, than corresponds to the maximum demand of the engine. In this way, the Do not stall or drown in fuel.

To improve the mixture formation, it can be advantageous if the introduction of fuel into the cylinder tangential to the cylinder bore and against their axis is inclined.

This results in a particularly favorable mixture formation, especially since the Ejection that is to be feared with liquid fuels does not play a role here. The advantageous cooling that occurs is also favorably distributed in this way.

Liquefied fuels such as butane, propane or Mixtures of gaseous hydrocarbons (propane, propylene, ethylene, etc.) such as them z. B. can be obtained from coke oven gases into consideration.

Claims (1)

PATENT CLAIMS: e.g. Method for operating gas machines with gas from fuels that are pressurized at air temperature liquefiable, but are gaseous at normal air pressure, characterized in that the Fuel is injected directly into the working cylinder in the liquid state will. a. Gas engine with an operating method according to claim z, characterized by the arrangement of a throttle body in the fuel supply line, the does not let more fuel through than the maximum requirement of the machine. is equivalent to. 3. Gas engine with an operating method according to claim z and claim z, characterized in that the fuel is tangential to the cylinder circumference and against the cylinder axis is inserted inclined. q .. gas engine with a method of operation according to claim z, in which the ignition takes place by means of a spark plug, characterized in that that all or part of the fuel is introduced in the vicinity of the spark plug.